Orphaned at three years old and unable to graduate from high school until he was 20, Calvin Bridges nonetheless became an original researcher whose work led to the formulation of many of the concepts of modern genetics, including proof of the part played by chromosomes in conveying hereditary characteristics. Described by his friends as a gentle, absent-minded, and even naive individual, Bridges conducted tireless laboratory research, breeding some 800 generations of the small tropical fruit fly Drosphila, leading to theoretical insights into the nature of heredity.

Bridges was born in Schuyler Falls, New York, a small town in the wilds of Lake Champlain. He was the only child of Leonard Victor Bridges, a man of modest means, and his wife, Amelia Charlotte Blackman. When Bridges was two years old, his mother died, followed by his father a year later. The boy was taken in by his paternal grandmother who placed...